Physical Topology

Physical Topology is depicted below. It is comprised of three QFX5100 devices running JunOS version 17.1. Two EX switches simulate customer CE devices.

VLAN over EVPN-VXLAN Physical Topology

Configuration

Loopback Reachability via IGP

VXLAN encapsulates Layer 2 Ethernet frames into IP before carrying them across the network.

The means that end-to-end IP reachability needs to be established between all Virtual Tunnel Endpoints (VTEP). In our scenario, QFX1, QFX2 and QFX3 will serve as VTEPs, so we’ll start with establishing Loopback IPs are reachable.

You can choose any IGP protocol of your choice, in our example we will be using IS-IS to provide loopback reachability:

QFX2 and QFX3 (Multi-Homed Site):

Multi-homed site requires Ethernet Segment Identifier (ESI) configuration that should be unique per site. This ESI value should be unique for each site.

We are also configuring Aggregate Ethernet interface. Although we could have placed ESI configuration on the physical ge-0/0/0 interface, AE will be useful in the future if you decided to augment the capacity and add more links to customer’s site. Creating AE bundles with a single link is a common practice employed by many service providers.